condition mean min max ZT0-3 9.515805 9.515805 9.515805 ZT4-7 6.47622 6.47622 6.47622 ZT8-11 13.15005 13.15005 13.15005 ZT12-15 23.076700000000002 23.076700000000002 23.076700000000002 ZT16-19 24.115049999999997 24.115049999999997 24.115049999999997 ZT20-23 11.93805 11.93805 11.93805